S7 Clearing multiple registers

[snydl0ga]

I have the need to clear several consecutive registers at the same time. I can't seem to find a function that will do that. I found the Move Block and the Fill but they move or fill from one group to another.

I need to do something like this:

Clear registers DB100.DBW100 through DB100.DBW200.

Maybe I didn't look hard enough...???

Lance

 

[dchartier]

Hello snydl0ga;
I am the first to agree that the solution I have used to do what you need to do is not the most elegant, but it works. I create a dummy DB, with an array of words (or bytes) initialized to 0. This is what I use as a Source (Bval parameter) for SFC21("Fill"). This allows me to initialize my Destination (Blk parameter)to 0. Just make the source as large as needed to cover all the registers of your destination (100 words in your example).
Hope this helps,
Daniel Chartier

 

[stevo]

Hi,
Try this:
write zero to MD204

     L 0

     T MB10

     

     CALL "FILL"

     SRCBLK :=P#M10.0 BYTE 1

     RET_VAL:=MW22

     BLK    :=P#M204.0 BYTE 4

     

     

You could probably use a Temp variable instead of "M"
addressing. Just change to your DB start address and area length, ie P#DB100.DBW100 WORD 100 in BLK

I think this should work ok

Steve

 

[stevo]

For the area length in the example "FILL" would be a waste of time as i could

 L 0

 T MD204

 

but you get the idea(i hope)

All the best

Steve

 

[SimonGoldsworthy]

"clear" is a temporary int, "return" is a temporary word. Note that in the following code the number of words cleared in DB100 is hard coded in the fill block parameters. If there is any chance that the area may change in size you could use pointers to the start and end of your data area and then contruct the anypointer for the block fill. The code would then need a re-compile to work with a different length of data area, instead of having to search and manually update the lengths.

L 0
T #clear
CALL SFC 21
BVAL :=#clear
RET_VAL:=#Return
BLK :=P#DB100.DBX 100.0 INT 101

 

[jacekd]

I create a dummy DB, with an array of words (or bytes) initialized to 0. This is what I use as a Source (Bval parameter) for SFC21("Fill").

All you need is just one byte initialized to 0 and you can clear as large area as S7 can handle with SFC21.

 

[snydl0ga]

Thanks ALL. I will give this a try when I get to work this morning.

Lance

 

[Amr Hassan]

i did yhis before using this function from the ti library

A M 37.0
JCN M027
CALL FC 88
IN0 :=DB2.DBW0
IN1 :=B#16#4
IN2 :=B#16#4
RET_VAL:=MW40
M027: NOP 0